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Space News Update — March 6, 2015 —

Contents

In the News

Story 1:

NASA Research Suggests Mars Once Had More Water than Earth’s Arctic

Ocean

Story 2:

Planet Found in a Quadruple Star System

Story 3:

NASA Spacecraft Becomes First to Orbit a Dwarf Planet

Departments

The Night Sky

ISS Sighting Opportunities

Space Calendar

NASA-TV Highlights

Food for Thought

Space Image of the Week

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1. NASA Research Suggests Mars Once Had More Water than Earth’s Arctic Ocean

A primitive ocean on Mars held more water than Earth’s Arctic Ocean, according to NASA scientists who, using ground-based observatories, measured water signatures in the Red Planet’s atmosphere.

Scientists have been searching for answers to why this vast water supply left the surface. Details of the observations and computations appear in Thursday’s edition of Science magazine.

“Our study provides a solid estimate of how much water Mars once had, by determining how much water was lost to space,” said Geronimo Villanueva, a scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and lead author of the new paper. “With this work, we can better understand the history of water on Mars.”

Perhaps about 4.3 billion years ago, Mars would have had enough water to cover its entire surface in a liquid layer about 450 feet (137 meters) deep. More likely, the water would have formed an ocean occupying almost half of Mars’ northern hemisphere, in some regions reaching depths greater than a mile (1.6 kilometers).

The new estimate is based on detailed observations made at the European Southern Observatory’s Very Large Telescope in Chile, and the W.M. Keck Observatory and NASA Infrared Telescope Facility in Hawaii. With these powerful instruments, the researchers distinguished the chemical signatures of two slightly different forms of water in Mars’ atmosphere. One is the familiar H2O. The other is HDO, a naturally occurring variation in which one hydrogen is replaced by a heavier form, called deuterium.

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By comparing the ratio of HDO to H2O in water on Mars today and comparing it with the ratio in water trapped in a Mars meteorite dating from about 4.5 billion years ago, scientists can measure the subsequent atmospheric changes and determine how much water has escaped into space.

The team mapped H2O and HDO levels several times over nearly six years, which is equal to approximately three Martian years. The resulting data produced global snapshots of each compound, as well as their ratio. These first-of-their-kind maps reveal regional variations called microclimates and seasonal changes, even though modern Mars is essentially a desert.

The research team was especially interested in regions near Mars’ north and south poles, because the polar ice caps hold the planet’s largest known water reservoir. The water stored there is thought to capture the evolution of Mars’ water during the wet Noachian period, which ended about 3.7 billion years ago, to the present.

From the measurements of atmospheric water in the near-polar region, the researchers determined the enrichment, or relative amounts of the two types of water, in the planet’s permanent ice caps. The enrichment of the ice caps told them how much water Mars must have lost – a volume 6.5 times larger than the volume in the polar caps now. That means the volume of Mars’ early ocean must have been at least 20 million cubic kilometers (5 million cubic miles).

Based on the surface of Mars today, a likely location for this water would be in the Northern Plains, considered a good candidate because of the low-lying ground. An ancient ocean there would have covered 19 percent of the planet’s surface. By comparison, the Atlantic Ocean occupies 17 percent of Earth’s surface.

“With Mars losing that much water, the planet was very likely wet for a longer period of time than was previously thought, suggesting it might have been habitable for longer,” said Michael Mumma, a senior scientist at Goddard and the second author on the paper.

NASA is studying Mars with a host of spacecraft and rovers under the agency’s Mars Exploration Program, including the Opportunity and Curiosity rovers, Odyssey and Mars Reconnaissance Orbiter spacecraft, and the MAVEN orbiter, which arrived at the Red Planet in September 2014 to study the planet’s upper atmosphere.

In 2016, a Mars lander mission called InSight will launch to take a first look into the deep interior of Mars. The agency also is participating in ESA’s (European Space Agency) 2016 and 2018 ExoMars missions, including providing telecommunication radios to ESA’s 2016 orbiter and a critical element of the astrobiology instrument on the 2018 ExoMars rover. NASA’s next rover, heading to Mars in 2020, will carry instruments to conduct unprecedented science and exploration technology investigations on the Red Planet.

NASA’s Mars Exploration Program seeks to characterize and understand Mars as a dynamic system, including its present and past environment, climate cycles, geology and biological potential. In parallel, NASA is developing the human spaceflight capabilities needed for future round-trip missions to Mars in the 2030s.

To view a video of this finding, visit http://youtu.be/WH8kHncLZwM

More information about NASA's Mars programs is online at http://www.nasa.gov/mars

Source: NASA Return to Contents

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2. Planet Found in a Quadruple Star System

Researchers wanting to know more about the influences of multiple stars on exoplanets have come up with a new case study: a planet in a four-star system.

The discovery was made at Palomar Observatory using two new adaptive optics technologies that compensate for the blurring effects of Earth's atmosphere: the robotic Robo-AO adaptive optics system, developed under the leadership of Dr. Christoph Baranec of the University of Hawaii at Manoa's Institute for Astronomy, and the PALM-3000 extreme adaptive optics system, developed by a team at Caltech and NASA's Jet Propulsion Laboratory (JPL) that also included Baranec.

The newfound four-star planetary system, called 30 Ari, is located 136 light-years away in the constellation Aries. The system's gaseous planet is enormous, with 10 times the mass of Jupiter, and orbits its primary star every 335 days.

The new study, published in the Astronomical Journal, brings the number of known stars in the 30 Ari system from three to four. This discovery suggests that planets in quadruple star systems might be less rare than once thought.

"About four percent of solar-type stars are in quadruple systems, which is up from previous estimates because observational techniques are steadily improving," said co-author Andrei Tokovinin of the Cerro Tololo Inter-American Observatory in Chile.

The newly discovered fourth star, whose distance from the planet is 23 times the Sun-Earth distance, does not appear to have impacted the orbit of the planet. The exact reason for this is uncertain, so the team is planning

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further observations to better understand the orbit of the newly discovered star and its complicated family dynamics.

Were it possible to see the skies from this world, the four stars would look like one small sun and two very bright stars that would be visible in daylight. If viewed with a large enough telescope, one would see that one of those bright stars is actually a binary systemtwo stars orbiting each other.

In recent years, dozens of planetary systems with two or three host stars have been found, including those that would have twin sunsets reminiscent of the ones on the fictional Star Wars planet Tatooine. Finding planets with multiple stars isn't too much of a surprise, considering that binary stars are more common in our galaxy than single stars such as our sun.

Lead author Lewis Roberts (JPL) and his colleagues want to understand the effects that multiple stars can have on their developing youthful planets. Evidence suggests that stellar companions can influence the fate of planets by changing the planets' orbits and even triggering some to grow more massive.

The "hot Jupiter" planets that whip around their stars in just days, for example, might be gently nudged closer to their primary star by the gravitational hand of a stellar companion. "This result strengthens the connection between multiple star systems and massive planets," said Roberts.

"The discovery of this exciting system is only possible when we quickly scan through large numbers of potential targets," said Baranec. "At the moment, Robo-AO is the only instrument that can give us the necessary combination of resolution and efficiency. Once we discover something interesting with Robo-AO, we can follow up with the 'Formula 1' systems, like PALM-3000 or the SCExAO system at the Subaru Telescope in Hawaii, to obtain the absolute sharpest images possible. Additionally, we're planning to bring a new, more powerful Robo-AO system to the University of Hawaii 2.2-m telescope to leverage the pristine skies of Maunakea, Hawaii. We'll use it for even larger surveys and follow-up observations of asteroids and supernovae discovered by ATLAS on Mauna Loa and Haleakala."

ATLAS (Asteroid Terrestrial-impact Last Alert System?) is an asteroid-impact early-warning system being developed by the University of Hawaii with funding from NASA.? When completed in 2015, it will consist of two telescopes, one on Mauna Loa and the other on Haleakala, that will automatically scan the whole visible sky several times every night looking for moving objects. For more information, go to fallingstar.com.

For information about Robo-AO, go to www.ifa.hawaii.edu/Robo-AO/.

Source: Spaceref.com Return to Contents

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3. NASA Spacecraft Becomes First to Orbit a Dwarf Planet

NASA's Dawn spacecraft has become the first mission to achieve orbit around a dwarf planet. The spacecraft was approximately 38,000 miles (61,000 kilometers) from Ceres when it was captured by the dwarf planet’s gravity at about 4:39 a.m. PST (7:39 a.m. EST) Friday.

Mission controllers at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California received a signal from the spacecraft at 5:36 a.m. PST (8:36 a.m. EST) that Dawn was healthy and thrusting with its ion engine, the indicator Dawn had entered orbit as planned.

"Since its discovery in 1801, Ceres was known as a planet, then an asteroid and later a dwarf planet," said Marc Rayman, Dawn chief engineer and mission director at JPL. "Now, after a journey of 3.1 billion miles (4.9 billion kilometers) and 7.5 years, Dawn calls Ceres, home."

In addition to being the first spacecraft to visit a dwarf planet, Dawn also has the distinction of being the first mission to orbit two extraterrestrial targets. From 2011 to 2012, the spacecraft explored the giant asteroid Vesta, delivering new insights and thousands of images from that distant world. Ceres and Vesta are the two most massive residents of our solar system’s main asteroid belt between Mars and Jupiter.

The most recent images received from the spacecraft, taken on March 1 show Ceres as a crescent, mostly in shadow because the spacecraft's trajectory put it on a side of Ceres that faces away from the sun until mid-April. When Dawn emerges from Ceres' dark side, it will deliver ever-sharper images as it spirals to lower orbits around the planet.

"We feel exhilarated," said Chris Russell, principal investigator of the Dawn mission at the University of California, Los Angeles (UCLA). "We have much to do over the next year and a half, but we are now on station with ample reserves, and a robust plan to obtain our science objectives."

Dawn's mission is managed by JPL for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team.

For a complete list of mission participants, visit: http://dawn.jpl.nasa.gov/mission

For more information about Dawn, visit: http://www.nasa.gov/dawn

Source: NASA Return to Contents

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The Night Sky

Friday, March 6

Venus and Mars in the western twilight have widened quite a bit — they're now 6° apart — following their conjunction two weeks ago. Look for faint Mars under Venus. The gap between them enlarges a little more each day.

As the stars come out at this time of year, look due south for Orion standing upright at his highest. As night deepens, dim Lepus, the Hare, emerges under his feet. Below Lepus is Columba, the Dove.

Saturday, March 7

Mutual event among Jupiter's moons. Telescope users can watch Europa occult (cross in front of) Io from 1:15 to 1:21 a.m. Sunday morning EST. The blend of the two dims by just 0.5 magnitude at mid-event. They're the pair of moons closest to Jupiter at the time. Then exactly one hour after the end of that event, Europa's shadow starts eclipsing Io for 6 minutes, dimming it by 0.8 magnitude at mid-eclipse.

Similar mutual events happen among Jupiter's moons through the rest of the month; see the March Sky & Telescope, page 53. If you're not in North America, here's where to get the whole list worldwide, sortable by visibility from your location. These "mutual event seasons" happen about every 6 years. The current one trails off later this spring.

Daylight-saving time begins at 2 a.m. Sunday morning for most of the U. S. and Canada. Clocks spring ahead one hour.

Sunday, March 8

Now that the Moon is gone from the early-evening sky, have another look for Comet Lovejoy! It's crossing Cassiopeia and still 6th magnitude, fading more slowly than predicted. Plan to go out right after dark. See article and finder chart: Comet Lovejoy Shines On.

Monday, March 9

Ganymede, Jupiter's biggest moon, enters onto Jupiter's face at 10:10 p.m. EDT and exits at 1:47 a.m. EDT. Its black shadow trails almost three hours behind, crossing Jupiter from 1:05 to 4:43 a.m. EDT. (Subtract 3 hours to get Pacific times; this event is more convenient for the West Coast.)

Source: Sky & Telescope Return to Contents

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ISS Sighting Opportunities

For Denver:

Date Visible Max

Height Appears Disappears

Sun Mar 8, 6:54 AM 3 min 25° 11 above S 25 above SE

Mon Mar 9, 6:02 AM 2 min 13° 10 above SSE 12 above ESE

Tue Mar 10, 6:43 AM 4 min 66° 10 above SW 40 above ENE

Sighting information for other cities can be found at NASA’s Satellite Sighting Information

NASA-TV Highlights (all times Eastern Daylight Time)

Friday, March 6

3 p.m., Replay of the ISS Expedition 43 Crew News Conference at Star City, Russia (all channels)

3:50 p.m., Video File of the ISS Expedition 43 Crew Ceremonial Activities in Star City and Moscow, Russia (all channels)

6 p.m., 7:30 p.m., 9:30 p.m. Replay of Video File of the ISS Expedition 43 Crew Qualification Exams at the Gagarin Cosmonaut Training Center in Star City, Russia (all channels)

Saturday, March 7

1 a.m., 3:30 a.m., 7:30 a.m., 10 a.m., 11:30 a.m., 1 p.m., 3:30 p.m., 6 p.m., 7:30 p.m., 9:30 p.m., Replay of Video File of the ISS Expedition 43 Crew Qualification Exams at the Gagarin Cosmonaut Training Center in Star City, Russia (all channels)

8 a.m., Replay of the “Welcoming Remarks and Keynote Address” for NACA Centenary: A Symposium on 100 Years of Aerospace Research and Development at the Smithsonian’s National Air and Space Museum, (3/3/2015) (NTV-2 (Education))

8:50 a.m., Replay of the “Panel Discussion, Setting The Stage” from the NACA Centenary: A Symposium on 100 Years of Aerospace Research and Development from the Smithsonian’s National Air and Space Museum (3/3/2015) (NTV-2 (Education))

11 a.m., Replay of the “Early History of NACA” from the NACA Centenary: A Symposium on 100 Years of Aerospace Research and Development from the Smithsonian’s National Air and Space Museum, (3/3/2015) (NTV-2 (Education))

12:30 p.m., Replay of “Flight Test and Research” from the NACA Centenary: A Symposium on 100 Years of Aerospace Research and Development from the Smithsonian’s National Air and Space Museum (3/3/2015) (NTV-2 (Education))

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2 p.m., Replay of the “Keynote Address: The NACA in the 1930’s - Trailblazing the Technical World of Aerodynamics” from the NACA Centenary: A Symposium on 100 Years of Aerospace Research and Development from the Smithsonian’s National Air and Space Museum (3/4/20 (NTV-2 (Education))

3 p.m., Replay of the “Key Aspects of NACA Research” from the NACA Centenary: A Symposium on 100 Years of Aerospace Research and Development from the Smithsonian’s National Air and Space Museum - (3/4/2015) (NTV-2 (Education))

4:45 p.m., Replay of “Transformations” from the NACA Centenary: A Symposium on 100 Years of Aerospace Research and Development from the Smithsonian’s National Air and Space Museum, - (3/4/2015) (NTV-2 (Education))

8 p.m., Replay of “The Next Assignment: A Panel Discussion” from the NACA Centenary: A Symposium on 100 Years of Aerospace Research and Development from the Smithsonian’s National Air and Space Museum (3/4/2015) (NTV-2 (Education))

Watch NASA TV on the Net by going to the NASA website.

Return to Contents

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Space Calendar

Mar 06 - [Mar 03] Dawn, Ceres Arrival Mar 06 - Comet 84P/Giclas At Opposition (3.284 AU) Mar 06 - Comet P/2013 TW5 (Spacewatch) At Opposition (5.047 AU) Mar 06 - Asteroid 7 Iris At Opposition (8.5 Magnitude) Mar 06 - Asteroid 2015 DT Near-Earth Flyby (0.028 AU) Mar 06 - Asteroid 8103 Fermi Closest Approach To Earth (1.965 AU) Mar 06 - Asteroid 2742 Gibson Closest Approach To Earth (1.991 AU) Mar 06 - Michelangelo's 540th Birthday (1475) Mar 07 - Comet P/2012 SB6 (Lemmon) At Opposition (3.828 AU) Mar 07 - Asteroid 1620 Geographos Closest Approach To Earth (0.238 AU) Mar 07 - Asteroid 2531 Cambridge Closest Approach To Earth (1.887 AU) Mar 07 - Asteroid 1258 Sicilia Closest Approach To Earth (2.314 AU) Mar 07 - Stanley Miller's 85th Birthday (1930) Mar 07-14 - 2015 IEEE Aerospace Conference, Big Sky, Montana Mar 08 - Daylight Saving - Set Clock Ahead 1 Hour (United States) Mar 08 - Comet 32P/Comas Sola At Opposition (1.389 AU) Mar 08 - Comet C/2014 F2 (Tenagra) At Opposition (3.952 AU)

Mar 08 - [Feb 28] Asteroid 2015 DK200 Near-Earth Flyby (0.018 AU) Mar 08 - Asteroid 3200 Phaethon Closest Approach To Earth (0.796 AU) Mar 08 - Asteroid 99942 Apophis Closest Approach To Earth (1.017 AU) Mar 08 - Asteroid 11836 Eileen Closest Approach To Earth (1.584) Mar 08 - Asteroid 1631 Kopff Closest Approach To Earth (1.709 AU) Mar 08 - Asteroid 216 Kleopatra Closest Approach To Earth (2.211 AU) Mar 08 - Asteroid 3106 Morabito Closest Approach To Earth (2.425 AU) Mar 09 - Comet C/2014 R4 (Gibbs) At Opposition (1.833 AU) Mar 09 - Asteroid 68363 (2001 OR49) Occults HIP 26616 (6.4. Magnitude Star) Mar 09 - Asteroid 2015 DS Near-Earth Flyby (0.044 AU) Mar 09 - Asteroid 6790 Pingouin Closest Approach To Earth (1.658 AU) Mar 09 - Asteroid 2614 Torrence Closest Approach To Earth (1.733 AU) Mar 09 - Asteroid 73511 Lovas Closest Approach To Earth (2.335 AU)

Stanley Miller

Source: JPL Space Calendar Return to Contents

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Food for Thought

The Green Lungs of Our Planet are Changing

Are leaves and buds developing earlier in the spring? And do leaves stay on the trees longer in autumn? Do steppe ecosystems remaining green longer and are the savannas becoming drier and drier?

In fact, over recent decades, the growing seasons have changed everywhere around the world. This was determined by a doctoral candidate at the Goethe University as part of an international collaboration based on satellite data. The results are expected to have consequences for agriculture, interactions between species, the functioning of ecosystems, and the exchange of carbon dioxide and energy between the land surface and the atmosphere.

"There is almost no part of the Earth that is not affected by these changes", explains Robert Buitenwerf, doctoral candidate at the Institute for Physical Geography at the Goethe University. He has evaluated satellite data from 1981 to 2012 with regard to 21 parameters on vegetation activity, in order to determine the point in time, the duration, and the intensity of growth from the northernmost conifer forests to tropical rain forests. His conclusion: On 54 percent of the land surface, at least one parameter of vegetation activity has moved away from the mean value by more than two standard deviations.

As reported by researchers from Frankfurt, Freiburg and New Zealand in the current edition of the professional journal Nature Climate Change, leaves are now sprouting earlier in most of the climate zones of the far north. Although they are also dropped somewhat earlier in autumn, the overall vegetation period has grown longer. On the other hand, in our latitudes, trees and shrubs are losing their leaves later than they have up to now.

To date, not much research has been conducted on the regions of the southern hemisphere. In those areas, the researchers found that in several savannas of South America, southern Africa and Australia, the vegetation activity has decreased during dry seasons. "Although these savannas have similar vegetation and comparable climates, the changes in vegetation activity differ. That may be attributable to the differences in the functioning of the respective ecosystems", says Buitenwerf.

In this respect, the seasonal distribution of leaf growth constitutes a sensitive indicator: it indicates how various ecosystems react to changes in the environment. "Although vegetation changes in the northern hemisphere have conclusively been attributed to climate change by other studies, attributing all the changes found in our study would require a more complex analysis," Buitenwerf emphasizes. In the northern hemisphere it has already been shown that species whose life cycles depend on the vegetation period are endangered by these severe changes. Consequences for species in the southern hemisphere are as yet unclear.

Source: Spaceref.com Return to Contents

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Space Image of the Week

Enhanced Color Caloris

Explanation: The sprawling Caloris basin on Mercury is one of the solar system's largest impact basins, created during the early history of the solar system by the impact of a large asteroid-sized body. The multi-featured, fractured basin spans about 1,500 kilometers in this enhanced color mosaic based on image data from the Mercury-orbiting MESSENGER spacecraft. Mercury's youngest large impact basin, Caloris was subsequently filled in by lavas that appear orange in the mosaic. Craters made after the flooding have excavated material from beneath the surface lavas. Seen as contrasting blue hues, they likely offer a glimpse of the original basin floor material. Analysis of these craters suggests the thickness of the covering volcanic lava to be 2.5-3.5 kilometers. Orange splotches around the basin's perimeter are thought to be volcanic vents.

Image Credit: NASA, Johns Hopkins Univ. APL, Arizona State U., CIW

Source: Astronomy Picture of the Day Return to Contents